1. Field of the Invention
This invention relates generally to sewing machines and more particularly to an improved high speed industrial sewing machine of the type employed to produce a seam along and around the edge of a workpiece as it is progressively fed through the machine.
2. Background of the Invention
Overedge sewing machines are widely used, particularly in industrial sewing operations, to form a one, two, or three thread seam along the free edge of the workpiece. In operation, these machines pass successive loops of a needle thread through the workpiece at spaced intervals along a line spaced inwardly from and parallel to the edge of the workpiece, with the successive loops being either interlooped with themselves or with one or two looper threads around the edge to complete the overedge seam.
As with any commercial operation, the speed of an industrial sewing machine is an important consideration. This factor has been largely responsible for the widespread acceptance of the overedge machine which traditionally has been a high speed machine. While refinement in existing machine designs has made possible the operation of overedge machines at rates in excess of seven thousand stitches per minute, practical limitations both as to stress and acceptable noise levels, made it clear that further substantial increases in speed were not practical with the prior art machine designs. It is, therefore, a primary object of the present invention to produce an improved high speed overedge sewing machine.
Another object of the invention is to provide such a machine capable of operating at very high speeds without the production of excessive noise or vibration.
Another object is to provide such a machine in which shaft driven connecting rods mounted in fixed planes are employed to drive the working elements of the machine.
Another object is to provide such a machine employing an improved material feed mechanism for feeding the work material through the machine.
Another object is to provide such a machine including an improved means for lubricating relative inaccessible components thereof.
Another object of the invention is to provided such a machine employing a main input shaft and a miter gear driven auxiliary shaft for driving the working components of the machine.